YouMail, a company that delivers enhanced voicemail and caller-ID functionality to smartphone users, recently crossed 2 billion calls answered, representing growth of more than 100 percent since July 2011. The company has 3.5 million registered users across iOS and Android, 2 million of which use the service each day.

Irvine isn’t exactly a fly-over city, but it’s a solid hour drive from the growing “LA tech” community and not exactly a hotbed of early-stage entrepreneurship. As much as Los Angeles still needs more institutional capital and infrastructure to support its startup ecosystem, Irvine is in another world. The city in the center of “the OC” has far more insurance companies and real estate investment firms than incubators and angel investors.

YouMail’s most popular features, and those which helped it overcome these geographic disadvantages, are voicemail receipts, human voice to text transcription, voicemail sharing, greet callers by name, and call blocking. The service is offered on a freemium model, with several paid pro tiers offering increasing storage and transcriptions per month.

“Just as GMail has made email a less frustrating and more intuitive experience for desktop users, YouMail is doing that for voice messaging on the smartphone,” says CEO Alex Quilici.

By offering human transcription, the company addresses the main complaint with services like Google Voice. Quilic claims that his company has been able to reduce error rates to between three and four percent, a stark difference than the 20 to 25 percent rates associated with most machine services. While at first glance, this might seem like a solution fraught with privacy concerns, for those professionals and high volume consumers who rely on voicemail, it’s a welcome improvement.

YouMail has just 10 employees, a level it has been able to maintain by building an extremely lean and stable platform that requires limited maintenance, according to its CEO. The not-so-little (in terms of success) company that could has raised $11.2 million since 2007 from Crunch Fund, Tech Coast Angels, Seimer Ventures, and VantagePoint Capital Partners, with the latest round being a $4.5 million series B in July 2011. Along the way, the company overcame bullying by some industry giants, including T-Mobile, Google, and Blackberry.

The most impressive thing about YouMail is that it actually might be saving the dying medium of voicemail, albeit maybe only temporarily. More and more frequently these days I hear some version of the voicemail greeting, “Please don’t leave me a message. Please send me a text.”

According to Quilic, users actually start receiving and opening more messages after signing up for the service. His explanation for this trend is that the service removes much of the friction throughout the process, such that calls are returned more quickly and frequently, leaving all parties more satisfied and more likely to return.

Personally, I’m not convinced that it will be enough to save voicemail as we currently know it, but I think it’s absolutely extending its usefulness. As YouMail evolves, and continues to offer additional features, it’s it the catbird seat to deliver the next generation solution. Along the way, expect the company to continue illustrating that innovation can happen anywhere.